Partially fill a large bowl with white school glue, add a few teaspoons of water and stir in a couple of drops of food coloring. In another glass, make up a solution of borax, one or two tablespoons to a cup. Stir this solution into the white glue mixture. The white glue is a polymer called polyvinyl acetate (PVA) and so should react with the sodium borate in the borax, essentially creating a single, giant molecule. The sodium borate/PVA compound should absorb all the water and, once the process is complete, the bowl should contain only a bouncy, squishy putty in a custom color.
Record how long squares of chocolate take to melt in a variety of different conditions: in and out of the shade, in the microwave and on top of aluminum foil in the sun. Try different types of chocolate, and place the melted chocolate in the freezer to re-solidify. Where possible use a thermometer to periodically record temperature. Explain the process of liquid turning to solid, and that the melting point of chocolate should be around 94 degrees, depending on sugar and milk additives.
Mix cornflower with water tinted with food coloring. Continue to stir the mixture, adding more cornflower or water as necessary, until the mixture thickens into a paste. Stirring the paste slowly allows water to flow between the tiny cornflower grains and so the substance acts like a liquid. Stirring quickly presses the grains together and prevents as much water from seeping through, making the substance closer to a thick paste. This process is multiplied by quick poking, making the substance act like a solid. Not only is the experiment a useful way to explore the different properties of solid and liquid objects, but it essentially explains the process at work in quicksand.
This classic experiment can get a little messy so make sure to stand well back and wear an apron or old clothes. Pour some cola into a bowl and drop a couple of Mento candies into the liquid, either in the bowl or the bottle for a more spectacular effect. Essentially, the surface area of a Mento candy is larger than most other sweets due to the tiny indentations covering them. When the candy hits the surface of the water, it dislodges water molecules and carbon dioxide bubbles are created in the gap. All these microscopic bubbles find a huge amount of space to cling on to on the surface of the Mento, so more are created than on a smoother surface. In addition, the Mento is denser than the water so sinks down to the bottom, creating more and more CO2 bubbles until the pressure become too much and a sticky geyser erupts from the bottle.